In the above technical field experiments have been carried out for several years in an attempt to treat cancerous tumours. These experiments have demonstated that the specific action of hyperthermia results in regression of the cancerous tumours. These experiments have also shown that hyperthermia increases the sensitivity of the cells to various chemical substances and thus enables use of chemo-therapy in the treatment of cancerous tumours. In addition, hyperthermia apparently also increases the effect of the ionizing radiations on the cancerous cells.
Microwaves may therefore be used, a priori, as therapeutic agents, because they may penetrate deeply into the biological tissue and thus reach remote tumours.
However, heretofore conducted experiments have disclosed a basic problem which is an incontestable obstacle to the development of such experiments on the biological tissue.
In fact, it has been observed that, due to their proximity to the applicator, surface tissues absorb more energy than deep tissues at whose level the hyperthermia must generally be directed to treat a tumour. To obtain a sufficient rise in temperature, of the order of 42.degree. to 44.degree. C. for example in deep tissues, it has been observed that the surface tissues and the skin in particular, underwent too great a rise in temperature, leading to degradation thereof and, moreover, imposing on the patients an intolerable physical stress with the durations of exposure generally employed.
Such a method and applicator for carrying it out cannot be developed until this problem has been solved so that it becomes possible to effect a deep local hyperthermia without inflicting a considerable rise in temperature intolerable for the surface tissues.
It is precisely an object of the present invention to find a solution to this problem by proposing a new type of applicator which enables the temperature of the surface tissues to be regulated whilst ensuring a deep hyperthermia.
It is an object of the invention to propose a new applicator which is of reliable design and easily produced at a particularly advantageous cost price.
It is another object of the invention to provide a new applicator which does not have dimensions substantially greater than means known at present, whilst making it possible to regulate as desired the temperature of the surface tissues.
A further object of the invention is to use means for attaining the purposes mentioned above which are capable of performing a second function of monitoring position, form in the general sense and dimensions of the local zones subjected to hyperthermia.